Flexible electrical conductor.



PATENTED JAN. 9, 1906.

G, E. SGHMIDMER.

FLEXIBLE ELECTRICAL CONDUCTOR.

APPLICATION FILED MAY 4, 1904.

711's fllorney UNITED STATES PATENT OFFICE.

GEORG EDUARD SOHMIDMER, OF N UREMBERG, GERMANY.

FLEXIBLE ELECTRICAL CON DUCTOR.

Specification of Letters Patent.

Patented Jan. 9, 1906.

Application filed May 4, 190 i. Serial No. 238,859.

To all whom it may concern:

Be it known that I, GEORG EDUARD SoHMIn- MER, of Nuremberg, Bavaria, Germany, have invented certain new and useful Improvements in Flexible Electrical Conductors; and I do hereby declare the following to be a full, clear, and exact description of my invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to telephone-cords for connecting the receiver of a telephone with the transmitting instrument. It is well known that cords of this character are in ordinary usage subjected to great torsional strains, owing to the receiver being turned back and forth when hung up and detached from the telephone-hook, and also to great tensioned strains due to the receiver being dropped or erked away from the transmitter to the full length of the cord. Where the conducting-wire in cords of this character is subj ected to strains in the manner described, they are frequently broken, thereby putting the telephone out of service.

It is the principal object of this invention to provide a telephone-cord wherein the electrical conducting-wire merely performs its function as such and is fully protected from all strains, which latter are sustained by a separate and independent supporting-cord.

To this end the invention consists in winding about a flexible core or cord in close helical convolutions the electrical conductor and in subsequently and collectively winding said conductor and cord in spaced convolutions about a central or supporting cord of flexible material.

One embodiment of my invention is shown in the accompanying drawing, wherein 1 designates the main or central cord composed of a plurality of spirally-wound strands of any suitable flexible material. 2 designates a second cord, also composed of a plurality of spirally-wound strands of flexible material. However, any form of cord which is flexible will perform the function required. The metallic conductor is shown in the form of a flat ribbon, (designated by 3,) although conductors of any cross-section may be used.

In constructing the improved cord the conductor 3 is first wound about the cord 2 in close helical convolutions, preferably bringing the marginal edges in close contact. The conductor 3 and its'cord 2 are next wound about the main or central cord 1 in spaced helical convolutionsthat is, in a manner to form a space or clearance between each spiral wind. This method of winding permits of flexing or bending the cord 1 in any way without crowding the adjacent conductor-strands together.

The central cord 1 is adapted for direct connection between the receiver and the transmitting instrument, so as to sustain any strain imposed and to perform the general function of a supporting-cord. It will be noted that the conductor 3 when wound in close convolutions to bring the edges in contact is substantially parallel to the central cord 1. Therefore when the latter is flexed or bent no bending action is imparted to the ribbon 3, as would be the case if the same were angularly disposed with respect to the cord. It will be understood, however, that while a slight angular disposition of the ribbon would result in bending the same slightly in flexing the cord 1 such construction would not be greatly detrimental and would be thoroughly practical, and therefore the term close is used in the sense that the edges of the ribbon are adjacent, but not necessarily in contact and contiguous, as a contact wind of the conductor is not essential to all embodiments of the invention. Therefore the invention in its broadest concept comprises a conductor helically or spirally wound about a flexible cord, both being collectively wound in separate spaced helical convolutions about a sec- 0nd or supporting cord.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. The herein-described product consisting of an inner or central flexible core and an outer conducting-cord wound about the core in spaced helical convolutions the said cord being composed of a central flexible core and a conductor wound about said core in close helical convolutions.

2. The herein-described product consisting of a core and an outer conducting-cord wound about the core in spaced helical convolutions, the said cord being composed of a flexible core and conductor wound about the said core in helical convolutions.

In testimony whereof I aflix my signature in presence of two witnesses.

GEORG EDUARD SCHHIDMER.

Witnesses ALEX WiELE, MAX SCHNEIDER. 

